I've uploaded an updated version of the Tuner Priority application today, there are no major bug fixes in it. The main aim of it was to work with the Vista beta. If you use it please ensure you have completed the configuration of at least 1 set of supported tuners otherwise you may encounter an error due to registry changes. I am holding off until beta 2 so that the Media Center registry is in somewhat more of a final state before I fix that.
Download
http://www.salloway.org.uk/mediacenter/util/index.htm